Master Nursery Eureka Planting Mix is ready-to-use as it comes from the bag. No additional ingredients are required. It is formulated to be used at planting time for flowers, shrubs, trees, and vegetables. Mix into native soil at planting time, or use straight from the bag when planting container plants. This product is ideally suited for azaleas, hollies, rhododendrons, and other acid loving plants. It contains fir bark, mushroom compost, perlite, and gypsum.